The GABAergic system contributes to the anxiolytic-like effect of essential oil from Cymbopogon citratus (lemongrass)

Unveiling the anxiolytic and analgesic effects of citronellal in Swiss mice: in vivo and in silico insights into COX and GABAA receptor pathways

This study aims to evaluate the analgesic and anxiolytic effects of citronellal (CTL) in Swiss mice using two new sensitive and economic mouse models along with possible molecular mechanisms through in silico studies. For this, we employed marble displacement and spiked-field apparatus to check the anxiolytic and analgesic effects, respectively. In silico studies were done against cyclooxygenase (COX) enzymes and GABAA receptor subunits. Findings suggest that the test sample CTL significantly reduced the number of marbles displaces (NMD), square crosses (NSC), paw massages (NPM), and escaping attempts (NEA) in animals than the control group. CTL exhibited better effects in the perforated-field study compared to the reference drug diclofenac sodium. In both cases, CTL (200 mg/kg) significantly reduced the test parameters when combined with the standard drugs (diazepam or diclofenac sodium). In in silico studies, CTL showed binding affinities of - 5.5, - 5.2, - 4.8, and - 4.8 kcal/mol with the COX1, COX2, and GABAA receptors (α2 and α3 subunits), respectively. Taken together, CTL may exert anxiolytic- analgesic-like effects on mice, possibly through the GABAA receptor and COXs interaction pathways. These new tools might be used to check the anxiolytic and analgesic properties of a wide variety of test substances.

Effect of aromatherapy with lemongrass (Cymbopogon citratus) on the anxiety of patients undergoing scaling and root planning: a randomized clinical trial

BACKGROUND

Anxiety is one of the most common factors that prevent people from going to a dentist. Therefore, finding a solution to better control stress has been an important issue in recent studies. Lemongrass positively affects the prevention of dental anxiety. The literature has shown that aromatherapy may regulate hemodynamic factors in patients. This study investigated the effects of the aroma of lemongrass on anxiety levels and hemodynamic factors during nonsurgical periodontal treatment.

METHODS

Thirty-eight patients were divided into two groups. First, the patients were asked to complete the Spielberger questionnaire to measure their level of dental anxiety. Blood pressure, heart rate, oxygen saturation, pain and satisfaction with treatment were evaluated. In the case group, nonsurgical periodontal therapy was performed while the patient inhaled the aroma of the lemongrass. Scaling was performed without intervention in the control group. The patients were then asked to complete the questionnaire again, and all the variables mentioned were remeasured.

RESULTS

Aromatherapy with lemongrass caused significant reductions in the systolic and diastolic blood pressure values, heart rate, and anxiety scores of patients. On the other hand, the differences in blood oxygen saturation changes, amount of pain and treatment satisfaction were insignificant between the two groups.

CONCLUSION

Inhalation of lemongrass essential oil appears beneficial for reducing anxiety and associated hemodynamic changes. Thus, aromatherapy with lemongrass may alleviate dental patients' anxiety.

TRIAL REGISTRATION

https://irct.behdasht.gov.ir/ IRCT20230615058492N2, 21/02/2024.

Ethnobotanical uses, phytochemistry and bioactivities of Cymbopogon plants: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbopogon (Poaceae) plants have been used for various purposes by many indigenous peoples in all continents. In particular, almost all species in the genus have traditionally been used as folk medicine to treat ailments. Traditional application records indicated that Cymbopogon might be used extensively to treat cold, dizziness, headache, loss of appetite, abdominal pain, rheumatism, diarrhea, whole grass for cold, sore throat, tracheitis and others.

AIMS OF THE REVIEW

Despite several research confirmed that Cymbopogon includes a range of active components, no review has been undertaken to consolidate information on its traditional uses, phytochemistry, pharmacology, and/or quality control. Thus this article aims to update a comprehensive review about the traditional uses, phytochemistry, pharmacology, cultivation techniques, economic benefits, trade, threats, and future conservation implications of Cymbopogon species. It may provide informative data for future development and further investigation of this important plant group.

MATERIALS AND METHODS

Traditional medicinal books and ethnomedicinal publications related to Cymbopogon from 1992 to 2023 were collated to investigate its ethnobotanical, phytochemical and pharmacological information. The online databases including Google Scholar, SciFinder, Web of Science, Scopus, Springer Link, PubMed, Wiley, China National Knowledge Infrastructure (CNKI), Baidu Scholar, and WanFang Database were screened.

RESULTS

Cymbopogon (Gramineae or Poaceae) plants have been grown worldwide. Traditional Chinese medicine and other medicinal systems believes that Cymbopogon has the effect of relieve a cough, analgesia, treating dizziness, traumatic injury and can relieve abdominal pain. A total of 153 compounds, including flavonoids, terpenoids, fatty acid and other compounds were isolated or identified from Cymbopogon species by phytochemical studies. The extracts or compounds from Cymbopogon have exhibited numerous biological activities such as antibacterial, antiinflammatory, antiviral, antineoplastic, antiarrhythmic, antidiabetic and other activities. The rich contents of citronellal, citronellol and geraniol found in Cymbopogon also provide significant nutritional benefits.

CONCLUSION

Based on their traditional uses, phytochemicals, and pharmacological activities, Cymbopogon plants are potential medicinal and edible resources with diverse pharmacological effects. Due to various advantages of this group, they possess huge application potential in food and pharmaceutical industries, and animal husbandry. Among them, citronella is very important in terms of economic development. Further comprehensive research to evaluate the medicinal properties of Cymbopogon species will be necessary for future development.

Madhuca indica oil-entrapped buoyant galactomannan hydrogel microspheres for controlling epileptic seizures

A stable Madhuca indica oil-in-water nanoemulsion (99-210 nm, zeta potential: > - 30 mV) was produced employing Tween 20 (surfactant) and Transcutol P (co-surfactant) (3:1). The nanoemulsion (oil: Smix = 3:7, 5:5, and 7:3) were subsequently incorporated into oxcarbazepine-loaded carboxymethylxanthan gum (DS = 1.23) dispersion. The hydrogel microspheres were formed using the ionic gelation process. Higher oil concentration had a considerable impact on particle size, drug entrapment efficiency, and buoyancy. The maximum 92 % drug entrapment efficiency was achieved with the microspheres having oil: Smix ratio 5:5. FESEM study revealed that the microspheres were spherical in shape and had an orange peel-like surface roughness. FTIR analysis revealed a hydrogen bonding interaction between drug and polymer. Thermal and x-ray examinations revealed the transformation of crystalline oxcarbazepine into an amorphous form. The microspheres had a buoyancy period of 7.5 h with corresponding release of around 83 % drug in 8 h in simulated stomach fluid, governed by supercase-II transport mechanism. In vivo neurobehavioral studies on PTZ-induced rats demonstrated that the microspheres outperformed drug suspension in terms of rotarod retention, number of crossings, and rearing activity in open field. Thus, Madhuca indica oil-in-water nanoemulsion-entrapped carboxymethyl xanthan gum microspheres appeared to be useful for monitoring oxcarbazepine release and managing epileptic seizures.

Multi-biological activity assessment and phytochemical characterization of an aqueous extract of the Cymbopogon citratus grown in Palestine

BACKGROUND

Plants have historically been a rich source of medicinal compounds, with many modern pharmaceuticals derived from botanical origins. In contemporary healthcare, there is a resurgence in utilizing botanical substances as recognized medicinal agents. This study delved into understanding the phytochemical makeup and the multifaceted biological activities of an aqueous extract from Cymbopogon citratus (C. citratus). The investigated activities were its effect on AMPA receptors, antioxidant capacity, anti-lipase, anti-α-amylase actions, cytotoxicity, and antimicrobial properties.

METHODS

The extract of C. citratus received a comprehensive investigation, which included the study of its phytochemical composition, assessment of its antioxidant and anti-lipase properties, evaluation of its capacity to inhibit α-amylase, analysis of its impact on cell viability, and assessment of its antimicrobial activity. The approaches are used to clarify the complex physiological and biochemical characteristics.

RESULTS

The results were compelling; receptor kinetics had a marked impact, notably on the GluA2 subunit. Regarding its medicinal potential, the extract demonstrated potent antioxidant and anti-diabetic activities with IC50 values of 15.13 and 101.14 µg/mL, respectively. Additionally, it displayed significant inhibitory effects on the lipase enzyme and showed cytotoxicity against the Hep3B cancer cell line, with IC50 values of 144.35 and 148.37 µg/mL. In contrast, its effects on the normal LX-2 cell line were minimal, indicating selectivity.

CONCLUSION

The aqueous extract of C. citratus shows promising therapeutic properties. The findings advocate for further research into its compounds for potential isolation, purification, and in-depth pharmacological studies, especially in areas like nervous system disorders, diabetes, obesity, and combating oxidative stress.

Pomegranate (Punica granatum L.) and its phytochemicals as anxiolytic; an underreported effect with therapeutic potential: A systematic review

Anxiety is a mental disorder characterized by excessive concern about possible future threats that, if prolonged, becomes a pathology that must be controlled through psychotherapy and medication. Currently, the pharmacological treatment for anxiety involves the use of antidepressants and benzodiazepines; however, these treatments often come with adverse effects. Thus, there is a need to seek natural compounds that can help alleviate anxiety and reduce these side effects. On the other hand, pomegranate (PG) fruit is known to have important health benefits, which have been compiled in several reviews. However, its anxiolytic effect has not been thoroughly studied, and clinical research on this topic is lacking. The aim of this work was to conduct a systematic review of studies exploring the anxiolytic-like effect of PG and its phytochemicals. Databases such as Pubmed, ScienceDirect, Springer link, Google scholar, Worldwide science, and Web of science were searched for articles using predetermined terms. Inclusion criteria were established, and original articles that met these criteria were selected. The data collected included information on PG part and variety, species, sample size, anxiety model, dose, route and time of administration, reference drug, main results, and the mechanisms of action. Fifty-nine studies were found that reported the anxiolytic-like effect of PG and its phytochemicals such as anthocyanins, flavonoids, tannins, organic acids, and xanthonoids. The literature suggests that the mechanisms of action behind this effect involved the inhibition of the GABAergic receptor, NMDA, CaMKII/CREB pathway; the reduction of oxidative stress, inhibiting TLR4 and nNOS; modulation of cytokines and the expression of NFkB, GAD67, and iNOS, as well as the activation of Nrf2 and AMPK. PG and some of its phytochemicals could be considered as a novel alternative for the treatment of pathological anxiety. This review is the first to document the anxiolytic-like effect of PG.

Comparative Studies on the Anti-Inflammatory and Apoptotic Activities of Four Greek Essential Oils: Involvement in the Regulation of NF-κΒ and Steroid Receptor Signaling

Essential oils (EOs) are well-known for their anti-fungal, anti-microbial, anti-inflammatory and relaxing activities. Steroid hormones, especially glucocorticoids, are also well-known for their anti-inflammatory activities and control of the hypothalamus-pituitary-adrenal (HPA) axis and glucose homeostasis. The biological activities of glucocorticoids render them the most widely prescribed anti-inflammatory drugs, despite their adverse side effects. In this study, comparative studies of the anti-inflammatory activities and interference with glucocorticoids receptor (GR) and estrogen receptor (ER) signaling of EOs from Greek Oregano, Melissa officinalis, Lavender and from the Chios Mastic, produced from the Greek endemic mastic tree, were performed in Human Embryonic Kidney 293 (HEK-293) cells. Chios Mastic (Mastiha) and oregano EOs exhibited the highest anti-inflammatory activities. The former showed a reduction in both NF-κB activity and protein levels. Mastic essential oil also caused a reduction in GR protein levels that may compensate for its boosting effect on dexamethasone (DEX)-induced GR transcriptional activation, ending up in no induction of the gluconeogenic phoshoenolpyruvate carboxykinase (PEPCK) protein levels that constitute the GR target. Oregano, Melissa officinalis and lavender EOs caused the suppression of the transcriptional activation of GR. Furthermore, the most active EO, that taken from Melissa officinalis, showed a reduction in both GR and PEPCK protein levels. Thus, the anti-inflammatory and anti-gluconeogenic activities of the EOs were uncovered, possibly via the regulation of GR signaling. Moreover, cytotoxic actions of Melissa officinalis and lavender EOs via the induction of mitochondrial-dependent apoptosis were revealed. Our results highlight these essentials oils' anti-inflammatory and apoptotic actions in relation to their implication on the regulation of steroid hormones' actions, uncovering their potential use in steroid therapy, with many applications in pharmaceutical and health industries as anti-cancer, anti-hyperglycemic and anti-inflammatory supplements.

Orofacial anti-hypernociceptive effect of citral in acute and persistent inflammatory models in rats

Orofacial pain has significant psychological and physiological effects. Citral (3,7-dimethyl-2,6-octadienal) is the main component of Cymbopogon citratus (DC) Stapf, an herb with analgesic properties. Although citral has been considered a potent analgesic, its putative effects on orofacial pain are still unknown.

OBJECTIVE

The objective of this study is to test the hypothesis that citral modulates orofacial pain using two experimental models: formalin-induced hyperalgesia in the vibrissae area and during persistent temporomandibular hypernociception using Complete Freund's Adjuvant - CFA test.

METHODS

For the formalin test, citral (100 and 300 mg/kg, oral gavage) or its vehicle (Tween 80, 1 %) were given 1 h before the formalin injection subcutaneously (sc) into the vibrissae area. For the CFA model, we analyzed the prophylactic (100 mg/kg of citral by oral gavage, 1 h before CFA injection) and the chronic therapeutic (citral treatment 1-hour post-CFA injection and daily post-CFA injection) effect of citral or its vehicle in animals treated with CFA for 8 days.

RESULTS

Citral caused a decrease in formalin-induced local inflammation and the time spent performing nociceptive behavior in a dose-dependent fashion. Similarly, prophylactic and therapeutic citral treatment decreased the CFA-induced persistent mechanical hypernociception in the temporomandibular area.

CONCLUSION

Our data strengthen the notion that citral plays a powerful antinociceptive role by decreasing orofacial hypernociception in formalin and CFA models.

Geraniol accelerates the gastric healing, minimizes ulcers recurrence, and reduces anxiolytic-like behavior in ulcerated rodents by oral or inhaled route

BACKGROUND

Geraniol (GE) is dietary acyclic monoterpene alcohol found in essential oils from aromatic plants with therapeutic value against gastric ulcers already described.

HYPOTHESIS/PURPOSE

To assess whether oral GE accelerates gastric healing or prevents ulcer recurrence, and to evaluate the hypothesis that GE promotes antiulcer effects by the inhaled route and that promotes changes in the behavior of ulcerated rodents.

METHODS

Gastric healing effects, underlining mechanisms, and behavioral changes were measured in80% acetic acid-induced gastric ulcer model in rats receiving GE by oral (30 mg/kg) or inhaled route (1 mg/L of air/min); whereas the effects of GE to avoid ulcer recurrence was evaluated in mice submitted to 10% acetic acid plus IL-1β ulcer.

RESULTS

GE administered by both routes accelerates gastric healing, increasing mucin and GSH levels, CAT, and GST activities, and reducing MPO activity. Moreover, oral, and inhaled GE minimized ulcer recurrence reducing gastric TNF and IL-6 levels and preserving mucin levels. Interestingly, the inhalation or oral intake of GE promotes anxiolytic-like effects in ulcerated rats.

CONCLUSION

Data altogether suggest that the GE accelerates gastric healing through the strengthening of protective factors of the gastric mucosa, promoting a quality healing that reduces the recurrence of the lesion. Besides, the anxiolytic-like effect of GE may also contribute to its gastric healing action since anxiety is recognized as one of the etiologic agents of ulcers.

Essential oils from Cymbopogon citratus and Lippia sidoides in the anesthetic induction and transport of ornamental fish Pterophyllum scalare

This study verified the effects of essential oils from Lippia sidoides (EOLS) and Cymbopogon citratus (EOCC) on the anesthesia of freshwater angelfish (Pterophyllum scalare) of two different sizes (juveniles I (0.82 g) and II (2.40 g)) and the transport (8 h) of juveniles II. Fish were exposed to different concentrations of EOLS and EOCC: 0, 10, 25, 50, 75, 100, 150, 200, and 250 mg L^-1. Ventilatory rate (VR) and transport for 8 h with 0, 10, and 15 mg L^-1 of each essential oil were evaluated in juveniles II. The major components found in EOLS and EOCC were carvacrol (44.50%) and α-citral (73.56%), respectively. The best sedation and anesthesia times for both essential oils were obtained with 10 and 25 mg L^-1 and 200 and 250 mg L^-1 for juveniles I and II, respectively. Fish sedated with EOLS had lower VR values than the other treatments. Blood glucose levels were higher in ornamental fish transported with 10 and 15 mg EOLS L^-1 and 15 mg EOCC L^-1. Hepatic glycogen values were higher in the control group. In general, fish transported with 10 mg EOLS L^-1 showed fewer gill histological alterations than other transported fish. When the type of lesion was evaluated, the highest gill alterations occurred in fish transported with EOCC. In conclusion, 10 mg EOLS L^-1 could be used to transport of juveniles II because although this concentration increased blood glucose levels, it decreased the VR and muscle glycogen levels and caused only mild alterations to the gills.

Aromas Influencing the GABAergic System

Aromas have a powerful influence in our everyday life and are known to exhibit an array of pharmacological properties, including anxiolytic, anti-stress, relaxing, and sedative effects. Numerous animal and human studies support the use of aromas and their constituents to reduce anxiety-related symptoms and/or behaviours. Although the exact mechanism of how these aromas exert their anxiolytic effects is not fully understood, the GABAergic system is thought to be primarily involved. The fragrance emitted from a number of plant essential oils has shown promise in recent studies in modulating GABAergic neurotransmission, with GABA_A receptors being the primary therapeutic target. This review will explore the anxiolytic and sedative properties of aromas found in common beverages, such as coffee, tea, and whisky as well aromas found in food, spices, volatile organic compounds, and popular botanicals and their constituents. In doing so, this review will focus on these aromas and their influence on the GABAergic system and provide greater insight into viable anxiety treatment options.

Use of essential oils in the diet of slow-growing broilers and their effects on performance

ABSTRACT This study proposes to examine the effect of supplementing the diet of slow-growing broilers with essential oils. A total of 270 one-day-old female chicks of the Pesadão Vermelho line, reared in an intensive system, were allocated to one of three treatments (1: Control, without addition of essential oils; 2: Feed supplemented with cinnamon essential oil; and 3: Feed supplemented with lemongrass essential oil) in a completely randomized design with nine replicates of 10 birds each. Growth performance variables were evaluated at 14, 28, 42, 56, and 70 days, whereas carcass yield, primal cuts, and internal organs were analyzed at 71 days of age. Data were subjected to analysis of variance and differences between means were compared using the Scott-Knott test at 5% probability. Supplementation with lemongrass essential oil improved the live weight of birds at 14, 28, and 42 days, as well as feed conversion and feed efficiency at 42 and 56 days of rearing (P<0.05). The treatments with cinnamon and lemongrass essential oils provided the highest thigh yields (P<0.05). The other evaluated variables did not show statistically significant differences (P>0.05) between treatments.

Exploring Pharmacological Mechanisms of Essential Oils on the Central Nervous System

Essential oils (EOs) have been traditionally used as ancient remedies to treat many health disorders due to their enormous biological activities. As mainstream allopathic medication currently used for CNS disorders is associated with adverse effects, the search to obtain safer alternatives as compared to the currently marketed therapies is of tremendous significance. Research conducted suggests that concurrent utilization of allopathic medicines and EOs is synergistically beneficial. Due to their inability to show untoward effects, various scientists have tried to elucidate the pharmacological mechanisms by which these oils exert beneficial effects on the CNS. In this regard, our review aims to improve the understanding of EOs' biological activity on the CNS and to highlight the significance of the utilization of EOs in neuronal disorders, thereby improving patient acceptability of EOs as therapeutic agents. Through data compilation from library searches and electronic databases such as PubMed, Google Scholar, etc., recent preclinical and clinical data, routes of administration, and the required or maximal dosage for the observation of beneficial effects are addressed. We have also highlighted the challenges that require attention for further improving patient compliance, research gaps, and the development of EO-based nanomedicine for targeted therapy and pharmacotherapy.

An aqueous extract of Canarium schweinfurthii attenuates seizures and potentiates sleep in mice: Evidence for involvement of GABA Pathway

About 30% of epileptic patients continue to have seizures. The present study investigates the anticonvulsant and sedative effects of an aqueous extract of C. schweinfurthii in mice. Anticonvulsant effects of C. schweinfurthii aqueous extract (0.01-300 mg/kg, p.o.) were tested against 4-aminopyridine (4-AP, 15 mg/kg, i.p.) -, pilocarpine (PILO, 380 mg/kg, i.p.) - and pentylenetetrazole (PTZ, 75 mg/kg, i.p.) -induced seizures, while sedative effects were tested on diazepam (35 mg/kg, i.p.)-induced sleep. Afterward, the most effective dose of the extract (11.9 mg/kg) was antagonized with N-methyl-β-carboline-3-carboxamide or flumazenil. In another set of experiments, mice were sacrificed for the estimation of GABA content and GABA-T activity in the cerebral cortex. The dose of the extract that protected 50% of mice (ED₅₀) against 4-AP, PILO, and PTZ was respectively 4.43 mg/kg (versus 12.01 for phenobarbital), 9.59 mg/kg (vs 8.67 for diazepam), and 2.12 mg/kg (vs 0.20 for clonazepam). Further, the ED₅₀ of the extract that increased the duration of sleep was 0.24 mg/kg (vs 0.84 for phenobarbital). N-methyl-β-carboline-3-carboxamide or flumazenil antagonized (p < 0.001) the anticonvulsant effect of C. schweinfurthii in PTZ-induced seizures and diazepam-induced sleep when compared to the negative control group. The extract at all doses increased (p < 0.001) the GABA content and decreased (p < 0.001) GABA-T activity. These findings suggest that C. schweinfurthii possesses anticonvulsant and sedative effects. These effects seem to be mediated via the modulation of the GABA neurotransmission. These data explain the use of this plant to treat epilepsy in Cameroon traditional medicine.

Cymbopogon citratus (DC.) Stapf, citral and geraniol exhibit anticonvulsant and neuroprotective effects in pentylenetetrazole-induced seizures in zebrafish

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbopogon citratus (DC.) Stapf (C. citratus) is consumed as an infusion in folk medicine due to its pharmacological properties and action in the central nervous system. Epilepsy is a neurological disorder that affects millions of people. Since the currently available antiepileptic drugs often cause undesirable side effects, new alternative therapeutic strategies based on medicinal plants have been proposed.

AIM OF THE STUDY

This study aimed to investigate the anticonvulsant and neuroprotective effects of C. citratus essential oil (EO) and hydroalcoholic extract (E1) from its leaves, as well as of its related compounds citral (CIT) and geraniol (GER) against the effects of pentylenetetrazole (PTZ) induced seizures in zebrafish (Danio rerio).

MATERIALS AND METHODS

To evaluate the anticonvulsant properties of the samples, adult animals were pre-treated (by immersion) and subsequently exposed to PTZ solution. The involvement of GABA_A receptors in the antiepileptic effects was investigated by the coadministration of flumazenil (FMZ), a known GABA_A receptor antagonist. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and nitric oxide (NO) were assessed in zebrafish brain homogenates after PTZ exposure.

RESULTS

All samples increased the latency time for the first seizure, which was reduced when animals were pretreated with FMZ, suggesting the involvement of GABA_A receptors in the observed properties. The association between CIT and GER at the lowest concentration studied showed a synergistic effect on the anticonvulsant activity. Decreases in MDA and NO levels and increases in GSH and CAT levels in the brain of treated animals suggested the neuroprotective effect of the compounds investigated.

CONCLUSIONS

Our results proved that C. citratus EO, E1, CIT and GER have anticonvulsant effects in zebrafish and could be used as a promising adjuvant therapeutic strategy for epilepsy treatment. Furthermore, zebrafish demonstrated to be an alternative animal model of epilepsy to evaluate the anticonvulsant and neuroprotective effects of C. citratus.

Essential Oil of Cymbopogon Citratus Grown in Umuahia: A Viable Candidate for Anti-Inflammatory and Antioxidant Therapy

The essential oils of Cymbopogon citratus (EOCC) has found use in medicine, food and chemical industry. This study attempts to provide evidence of its suitability for antioxidant and anti-inflammatory therapy. Total phenol and total flavonoid of EOCC was 49.83±0.39mg GAE/g of extract and 352.82±3.45 µg QEC/g of extract respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of its essential oil (EOCC) showed 25 peaks with myrcenyl acetate (9.703%), caryophyllene (8.997%), citronella (6.383%) been the most abundant. The in vitro anti-inflammatory assay using human red blood cell (HRBC) membrane stabilization shows that at 200µg/mL, the percentage inhibition of EOCC was significantly higher compared to diclofenac both for heat-induced and hypotonic induced haemolysis. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays showed a comparable and dose-dependent increase from 50 to 400 μg/mL in relation to vitamin C. Half maximal inhibitory concentration (IC50) of EOCC (73.16±12.89 μg/mL and 656.01±0.01 μmol Fe (II)/L) was remarkably higher compared to that of vitamin C (69.09±4.52 μg/mL and 246.79±0.01 μmol Fe (II)/L) both for DPPH and FRAP assays respectively. In conclusion, results from this study establish preliminary evidence on the therapeutic potential of EOCC in managing inflammation and oxidative stress caused by free radicals.

Role of Herbal Teas in Regulating Cellular Homeostasis and Autophagy and Their Implications in Regulating Overall Health

Tea is one of the most popular and widely consumed beverages worldwide, and possesses numerous potential health benefits. Herbal teas are well-known to contain an abundance of polyphenol antioxidants and other ingredients, thereby implicating protection and treatment against various ailments, and maintaining overall health in humans, although their mechanisms of action have not yet been fully identified. Autophagy is a conserved mechanism present in organisms that maintains basal cellular homeostasis and is essential in mediating the pathogenesis of several diseases, including cancer, type II diabetes, obesity, and Alzheimer’s disease. The increasing prevalence of these diseases, which could be attributed to the imbalance in the level of autophagy, presents a considerable challenge in the healthcare industry. Natural medicine stands as an effective, safe, and economical alternative in balancing autophagy and maintaining homeostasis. Tea is a part of the diet for many people, and it could mediate autophagy as well. Here, we aim to provide an updated overview of popular herbal teas’ health-promoting and disease healing properties and in-depth information on their relation to autophagy and its related signaling molecules. The present review sheds more light on the significance of herbal teas in regulating autophagy, thereby improving overall health.

Effects of Thai Local Ingredient Odorants, Litsea cubeba and Garlic Essential Oils, on Brainwaves and Moods

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor and fragrance of the famous tom yum and massaman dishes. While the biological activities of these ingredients have been investigated, including the antioxidant, anti-inflammatory, and antimicrobial activities, there is still a lack of understanding regarding the responses to the essential oils of these plants. To investigate the effects of essential oil inhalation on the brain and mood responses, electroencephalography was carried out during the non-task resting state, and self-assessment of the mood state was performed. The essential oils were prepared in several dilutions in the range of the supra-threshold level. The results show that Litsea cubeba oil inhalation showed a sedative effect, observed from alpha and beta wave power reductions. The frontal and temporal regions of the brain were involved in the wave alterations. Garlic oil increased the alpha wave power at lower concentrations; however, a sedative effect was also observed at higher concentrations. Lower dilution oil induced changes in the fast alpha activity in the frontal region. The alpha and beta wave powers were decreased with higher dilution oils, particularly in the temporal, parietal, and occipital regions. Both Litsea cubeba and turmeric oils resulted in better positive moods than garlic oil. Garlic oil caused more negative moods than the others. The psychophysiological activities and the related brain functions require further investigation. The knowledge obtained from this study may be used to design functional food products.

Anaesthetic Efficiency of Cymbopogon citratus Essential Oil and Clove Oil on Macrobrachium rosenbergii

&lt;b&gt;Background and Objective:&lt;/b&gt; Studies on plant herbs as alternatives to chemical anaesthetics in fish species are numerous, but little is known on crustaceans. A study was conducted to investigate the efficacy of &lt;i&gt;C. citratus&lt;/i&gt; Essential Oil (EO) on the induction and recovery of &lt;i&gt;M. rosenbergii&lt;/i&gt;. &lt;b&gt;Materials and Methods:&lt;/b&gt; The &lt;i&gt;C. citratus&lt;/i&gt; EO was obtained by hydrodistillation and analyzed using GC-MS. The prawns were exposed to &lt;i&gt;C. citratus&lt;/i&gt; EO and clove oil in 100-1000 and 200-1000 μL L&lt;sup&gt;1&lt;/sup&gt;, respectively. Different stages of induction and recovery times were recorded. &lt;b&gt;Results:&lt;/b&gt; In GC-MS, citral (78.47%) was detected as a major compound in &lt;i&gt;C. citratus&lt;/i&gt; EO. Prawns reached loss equilibrium at 500-1000 μL L&lt;sup&gt;1&lt;/sup&gt; &lt;i&gt;C. citratus&lt;/i&gt; EO within 15.55-6.52 min. Exposure of prawn to &lt;u&gt;<&lt;/u&gt;500 μL L&lt;sup&gt;1&lt;/sup&gt; &lt;i&gt;C. citratus&lt;/i&gt; EO resulted in a high survival rate (100-94%). In clove oil, all tested concentrations caused significant induction in &lt;i&gt;M. rosenbergii&lt;/i&gt; within 20.61-6.47 min. Recovery time and survival rate were significantly decreased with the increase of EO concentrations. The regression model showed the induction time in both anaesthetic agents was dependent on the concentration (R&lt;sup&gt;2 &lt;/sup&gt;= 0.86-0.96). The recovery time of &lt;i&gt;C. citratus&lt;/i&gt; EO-exposed prawn was dependent on the concentrations (R&lt;sup&gt;2 &lt;/sup&gt;= 0.59). &lt;b&gt;Conclusion:&lt;/b&gt; The study shows the potentiality of &lt;i&gt;C. citratus&lt;/i&gt; EO as a natural anaesthetic in &lt;i&gt;M. rosenbergii&lt;/i&gt;, although not as efficient as clove oil.

Anxiolytic properties of Cymbopogon citratus (DC.) stapf extract, essential oil and its constituents in zebrafish (Danio rerio)

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbopogon citratus (DC.) Stapf (Poaceae) leaves is often consumed as infusion in folk medicine due to its therapeutic properties. This plant is also rich in essential oil, which has several beneficial effects to the human health. It is known that medications commonly used to treat anxiety disorders cause undesirable side effects. Thus, it is important to evaluate the anxiolytic effects of natural products from plants, such as C. citratus, as an alternative therapy to treat these disorders.

OBJECTIVE

The aim of this study was to investigate the anxiolytic properties of C. citratus essential oil (EO), hydroalcoholic extract (E1), citral (CIT), geraniol (GER) and the mixture of these terpenoids, as well as its possible mechanism of action by using zebrafish as an anxiety model.

METHODS

Adult zebrafish were treated (by immersion) with C. citratus EO, E1, CIT and/or GER. The anxiolytic effects were analyzed by using the light-dark test. The mechanism involved in the anxiolytic effects was further investigated by the coadministration of flumazenil (FMZ), an antagonist of GABA_A receptors. The total polyphenols (phenolic and flavonoid compounds) content of E1 was determined by using spectrophotometric assays.

RESULTS

All analyzed samples showed a remarkable anxiolytic effect on zebrafish in the highest concentrations, as the animals showed a preference for the light side of the tank. Furthermore, the observed effect of EO, E1, CIT and GER was reversed by pre-treatment with FMZ, suggesting that GABAergic receptors were involved in the anxiolytic effect displayed by these samples. The association between CIT and GER in the lowest studied concentrations showed an interesting synergistic behavior on anxiolytic effect observed in light-dark test. Besides, it was demonstrated that E1 was constituted by phenolic and flavonoid compounds, which could be involved in the observed effect.

CONCLUSION

This work has proved that the low-cost zebrafish can be an adequate alternative as an animal model to evaluate the anxiolytic effect of C. citratus and its related compounds. Moreover, the involvement of GABA_A receptors could be responsible for the effect showed by the samples. These obtained results can potentially validate the ethnopharmacological use of C. citratus as a medicinal plant for the treatment of anxiety disorders in folk medicine.

Anxiety Therapeutic Interventions of β-Caryophyllene: A Laboratory-Based Study

The bicyclic sesquiterpene β-caryophyllene (BCP) has diverse biological activities, including antioxidant, anti-inflammatory, antidiabetic, and analgesic effects. This study evaluates anxiolytic, toxicity, and antioxidant effects of BCP using in vitro and in vivo test models. The anxiolytic effects were tested in Swiss albino mice ( Mus musculus) by applying the elevated plus-maze, rota-rod, light and dark, and hiding sphere models, while the toxicity was evaluated by brine shrimp ( Artemia salina) lethality bioassay. Additionally, the antioxidant capacity was tested by using 2,2-diphenyl-1-picrylhydrazyl radical, 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid hydroxyl radical scavenging, and the Saccharomyces cerevisiae test model. The results suggest that BCP exerted a dose-dependent anxiolytic-like effect on the experimental animals. It did not show toxicity in A. salina at 24 hours. BCP showed a concentration-dependent free-radical-scavenging capacity, similar to the standard antioxidant Trolox. It also showed protective and repair capacities against hydrogen peroxide-induced damaging effects in isogenic and wild-type S. cerevisiae strains. Taken together, BCP exerted antioxidant and protective effects, which can be targeted to treat neurological diseases and disorders such as anxiety.

Bergamot essential oil attenuate aluminum-induced anxiety-like behavior through antioxidation, anti-inflammatory and GABA regulation in rats

A large number of studies showed that aluminum (Al) has potential neurotoxicity to human and animal bodies. Al-treated animals showed anxiety-like behavior, oxidative stress, neuroinflammation and γ-aminobutyric acid (GABA) changes. Bergamot essential oil (BEO) is a kind of well-known plant extract from the fresh fruit of bergamot. Previous studies suggested that BEO improved mood and relieved symptoms of stress-induced anxiety. This study was designed to study the effects of BEO on anxiety-like behavior, oxidative stress, neuroinflammation and GABA system in aluminum trichloride (AlCl₃) treated rats. Results showed that AlCl₃ exposure induced anxiety-like behavior in the elevated plus maze and the open field test. Moreover, AlCl₃ exposure decreased the level of GABA and the activity of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in the hippocampus (HP) and the frontal cortex (FC). In addition, AlCl₃ exposure increased the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the HP and the FC. To the contrary, co-administration of BEO and AlCl₃ improved the anxiety-like behavior, GABA system, oxidative stress and neuroinflammation. These results indicated that BEO can alleviate the anxiety-like behavior of AlCl₃-exposed rats through the combined action of antioxidant, anti-inflammatory and GABA regulation.

Effects of essential oils on central nervous system: Focus on mental health

Essential oils have been used as remedies since ancient times for the treatment of numerous illnesses on account of their wide range of biological activities. Recent preclinical and clinical studies have shown varying pharmacological responses in the nervous system leading to anxiolytic, antidepressant, sedative, and anticonvulsant effects. Experimentation in animal models has evidenced the involvement of multiple neurotransmitter systems in the mode of action of essential oils, resulting in measurable physiological effects in the brain. Additionally, clinical trials have demonstrated the influence of essential oils in physiological parameters such as blood pressure, heart rate, respiratory rate, brain waves composition, and cortisol serum levels with concomitant psychological effects. Although there is growing evidence of measurable effects of essential oils in animal brains, more clinical research is required to validate their influence in the human central nervous system. This will enable the development of essential oil-based drugs for the treatment of mental illnesses such as depression, anxiety and dementia.

Effects of sweet orange aromatherapy on pain and anxiety during needle insertion among patients undergoing hemodialysis: A quasi-experimental study

PURPOSE

Patients undergoing hemodialysis experience pain and anxiety during needle insertion, and the scientific interest in aromatherapy in reducing pain and anxiety is increasing. Thus, this study aimed to determine the effects of sweet orange aromatherapy on pain and anxiety during needle insertion in hemodialysis.

DESIGN

Quasi-experimental, pretest, and posttest.

METHODS

This study was carried out among 50 patients with chronic kidney disease who were non-randomly assigned to either sweet orange aromatherapy or calm breathing in three outpatient hemodialysis centers in the Philippines between July and August 2015. The numeric rating scale and adapted state-trait anxiety inventory were utilized to measure pain and anxiety.

RESULTS

After the intervention, both the pain and anxiety scores were significantly lower for patients who received sweet orange aromatherapy than those who received calm breathing. The results obtained modest effect sizes that imply high practical significance.

CONCLUSION

The sweet orange aromatherapy can be effective in reducing pain and anxiety. Thus, this can be used by nurses as an alternative and complementary approach to reduce both pain and anxiety in painful procedures like needle insertion.

Cymbopogon citratus aqueous leaf extract attenuates neurobehavioral and biochemical changes induced by social defeat stress in mice

Objective

Psychosocial stress has been implicated in the genesis of psychiatric disorders such as memory deficits, depression, anxiety and addiction. Aqueous leaf extract of Cymbopogon citratus (CYC) otherwise known as lemongrass tea has antidepressant, anxiolytic and anti-amnesic effects in rodents. This study was designed to evaluate if C. citratus could reverse the neurobehavioral and biochemical derangements induced by social defeat stress (SDS) in the resident/intruder paradigm.

Methods

Intruder male mice were divided into five groups (n = 7): group 1 received saline (10 mL/kg, p.o.; non-stress control), group 2 also received saline (10 mL/kg, p.o.; SDS control) while groups 3–5 had C. citratus (50, 100 and 200 mg/kg, p.o.) daily for 14 d. The SDS was carried out 30 min after each treatment from day 7 to day 14 by exposing each intruder mouse in groups 2–5 to a 10 min confrontation in the home cage of an aggressive resident counterpart. The neurobehavioral features (spontaneous motor activity-SMA, anxiety, memory, social avoidance and depression were then evaluated. The concentrations of nitrite, malondialdehyde and glutathione as well as acetylcholinesterase activity in the brain tissues were also determined.

Results

C. citratus (50, 100 and 200 mg/kg) attenuated hypolocomotion, heightened anxiety, depressive-like symptom, memory deficit and social avoidance induced by SDS. The altered levels of oxidative stress and acetyl-cholinesterase in SDS-mice were positively modulated by C. citratus.

Conclusion

The results of this study suggest that C. citratus might mitigate psychosocial stress-induced neurologic diseases in susceptible individuals.

Citral-induced analgesia is associated with increased spinal serotonin, reduced spinal nociceptive signaling, and reduced systemic oxidative stress in arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Citral (3,7-dimethyl-2,6-octadienal) is the main component of Cymbopogon citratus (DC) Stapf, an herb with analgesic properties. Arthritic pain is the main unpleasant component of rheumatoid arthritis. The pharmacological approaches used to treat arthritic pain are often accompanied by adjuvant drugs or non-pharmacological treatments, showing a constant need in identifying new efficient analgesic drugs.

AIM OF THE STUDY

To test the hypothesis that citral, which is a monoterpenoid compound with therapeutic properties, reduces nociception, spinal pro-nociceptive and pro-inflammatory signaling, and systemic oxidative stress in arthritic rats.

MATERIALS AND METHODS

Complete Freund's adjuvant (CFA) was administrated in the left knee joint of rats. Oral treatment with citral was performed during eight days and mechanical allodynia was monitored during the period of treatment to evaluate the analgesic effect of citral. We assessed the levels of serotonin (5-hydroxytryptamine, 5-HT) in the lumbar dorsal horn of the spinal cord (DHSC) and the profiles of expression of the glycogen synthase kinase-3β (GSK3β), which is a 5-HT-regulated intracellular protein, and of the stress-activated protein kinase (SAPK)/jun N-terminal kinase (JNK) in the DHSC. Plasma levels of superoxide dismutase (SOD) were assessed as an indicator of oxidative stress.

RESULTS

Administration of CFA induced mechanical allodynia associated with reduced spinal GSK3β phosphorylation, increased spinal SAPK/JNK phosphorylation, and increased plasma SOD levels. Oral administration of citral reversed mechanical allodynia, increased endogenous spinal 5-HT levels, reduced spinal SAPK/JNK phosphorylation, and reduced plasma SOD levels.

CONCLUSION

Citral shows anti-nociceptive effects in an animal model of arthritic pain by modulating spinal nociceptive signaling.

The Effects of Essential Oils and Terpenes in Relation to Their Routes of Intake and Application

Essential oils have been used in multiple ways, i.e., inhaling, topically applying on the skin, and drinking. Thus, there are three major routes of intake or application involved: the olfactory system, the skin, and the gastro-intestinal system. Understanding these routes is important for clarifying the mechanisms of action of essential oils. Here we summarize the three systems involved, and the effects of essential oils and their constituents at the cellular and systems level. Many factors affect the rate of uptake of each chemical constituent included in essential oils. It is important to determine how much of each constituent is included in an essential oil and to use single chemical compounds to precisely test their effects. Studies have shown synergistic influences of the constituents, which affect the mechanisms of action of the essential oil constituents. For the skin and digestive system, the chemical components of essential oils can directly activate gamma aminobutyric acid (GABA) receptors and transient receptor potential channels (TRP) channels, whereas in the olfactory system, chemical components activate olfactory receptors. Here, GABA receptors and TRP channels could play a role, mostly when the signals are transferred to the olfactory bulb and the brain.

Anxiolytic Effect of Essential Oils and Their Constituents: A Review

Essential oils are usually used in aromatherapy to alleviate anxiety symptoms. In comparison to traditional drugs, essential oils have fewer side effects and more diversified application ways, including inhalation. This review provides a comprehensive overview of studies on anxiolytic effects of essential oils in preclinical and clinical trials. Most of the essential oils used in clinical studies have been proven to be anxiolytic in animal models. Inhalation and oral administration were two common methods for essential oil administration in preclinical and clinical trials. Massage was only used in the clinical trials, while intraperitoneal injection was only used in the preclinical trails. In addition to essential oils that are commonly used in aromatherapy, essential oils from many folk medicinal plants have also been reported to be anxiolytic. More than 20 compounds derived from essential oils have shown an anxiolytic effect in rodents, while two-thirds of them are alcohols and terpenes. Monoamine neurotransmitters, amino acid neurotransmitters, and the hypothalamic-pituitary-adrenal axis are thought to play important roles in the anxiolytic effects of essential oils.

Evaluation of the anticonvulsant and anxiolytic-like activities of aqueous leaf extract of Cymbopogon citratus in mice

Background Anxiety is a common ailment of high co-morbidity with epilepsy, a chronic neurologic disease characterized by recurrent seizures. Current drugs used for these conditions have several limitations such as disabling side effects, relapse, and ineffectiveness in certain population necessitating the search for alternative options. The aqueous leaf extract of Cymbopogon citratus (CYC) is widely used for its various health-promoting effects including relief of seizures and anxiety in ethnomedicine. This present study describes its effects on convulsions, anxiety-like behaviors, and social interaction in mice. Methods Male Swiss mice were pretreated orally with CYC (25, 50, and 100 mg/kg), diazepam (1 mg/kg), or distilled water (10 mL/kg) 60 min before induction of convulsions with intraperitoneal (i.p.) injection of picrotoxin (10 mg/kg), pentylenetetrazole (PTZ; 85 mg/kg), or isoniazid (300 mg/kg). The animals were then observed for the occurrence of seizure for 30 min or 2 h for isoniazid. The effects of CYC on anxiety-like behaviors, social interaction, and spontaneous motor activity (SMA) were evaluated in naive mice. Results CYC (25-100 mg/kg) did not prevent convulsions nor delay the latency to convulsions induced by picrotoxin, PTZ, or isoniazid. Pretreatment with CYC (50 and 100 mg/kg, p.o) produced anxiolytic-like effect, decreased SMA, and also enhanced social interaction behavior in naive mice. Conclusions The results of this study suggest that CYC did not exhibit an anticonvulsant property in mice injected with picrotoxin, PTZ, or isoniazid, but its anxiolytic-like activity and social interaction-promoting effect might be of benefit as an adjuvant in improving the quality of life of epileptic patients.

fMRI-Based Brain Responses to Olfactory Stimulation with Two Putatively Orexigenic Functional Food Ingredients at Two Different Concentrations in the Pig Model

Natural plant extracts are increasingly used as functional feed ingredients in animal husbandry and food ingredients in human alternative medicine to improve welfare and health. We investigated in 20 growing pigs via functional magnetic resonance imaging (fMRI) the brain blood oxygen level-dependent (BOLD) responses to olfactory stimulation with two sensory functional feed ingredients, A and B, at two different concentrations. Functional ingredient A contained extracts from Citrus sinensis (60% to 80%), and ingredient B contained a mixture of extracts Oreganum vulgarae (40% to 55%) and Cymbopogon flexuosus (20% to 25%). Increased concentration of ingredients induced a higher activation in reward and cognitive areas compared to lower concentrations. Moreover, considering both ingredients at the highest concentration, the ingredient A elicited higher brain responses in brain areas involved in hedonism/pleasantness compared to ingredient B, and more specifically in the caudate nucleus and orbitofrontal cortex. Our findings shed new light in the scope of emotion regulation through olfactory modulation via sensory functional ingredients, which opens the way to further preclinical studies in animal models and translational research in the context of nutrition, welfare, and health. PRACTICAL APPLICATION: Functional food/feed ingredients are gaining interest for improving health and welfare in humans and animals. Besides representing an alternative to antibiotics for example, food ingredients and their sensory characteristics might have a positive impact on emotions and consequently on well-being. Functional brain imaging in large animals such as in the pig model is a promising approach to investigate the central and behavioural effects of food ingredients, and determine the most effective blends and concentrations to modulate internal and emotional states.

Nectandra grandiflora essential oil and its isolated sesquiterpenoids minimize anxiety-related behaviors in mice through GABAergic mechanisms

Nectandra grandiflora Ness (Lauraceae) essential oil (EO) main constituent, the sesquiterpenoid (+)-dehydrofukinone (DHF), has sedative and anticonvulsant effects through GABAergic mechanisms. Other DHF-related sesquiterpenoids have been identified in the EO, such as, dehydrofukinone epoxide (DFX), eremophil-11-en-10-ol (ERM) and selin-11-en-4-α-ol (SEL). However, the neuronal effects of these compounds in mammals remain unknown. Therefore, the aim of this study was to evaluate the anxiolytic potential of the N. grandiflora EO and the isolated compounds in in mice. For this purpose, mice were administered orally with vehicle, 10, 30 or 100 mg/kg EO, DHF, DFX, ERM or SEL or 1 mg/kg diazepam. Locomotion and ethological parameters in the open field (OF) and elevated plus maze (EPM) were recorded. We also examined the effect of DFX, ERM and SEL on the membrane potential and calcium influx in synaptosomes, and the presence of the compounds in the cortical tissue using gas chromatography. EOs and isolated compounds reduced anxiety-related parameters in the EPM (open arms time and entries, end activity, head dipping) and OF (center time and entries, total rearing, unprotected rearing, sniffing, grooming) without alter ambulation or induce sedation. Flumazenil (2 mg/kg, i.p.) altered the anxiolytic-like effect of all treatments and vanished the DFX, ERM and SEL-induced changes in membrane potential. However, FMZ did not blocked the DFX-, ERM- and SEL-induced inhibition of calcium influx. Therefore, our results suggest that N. grandiflora EO and isolated compounds induced anxiolytic-like effect in mice due to positive modulation of GABAa receptors and/or inhibition of neuronal calcium influx.

Medicinal Plants Used in the Treatment of Mental and Neurological Disorders in Ghana

Ethnopharmacological Relevance

Mental and neurological disorders are a serious public health challenge globally, particularly in developing countries where cultural factors and limited access to standard healthcare have led to a reliance on traditional medicines. However, ethnopharmacological characterization of traditional medicines used to treat these diseases is lacking. In this study, an ethnobotanical description of plant species used in treating mental and neurological disorders in Ghana and an update of their experimentally validated pharmacological relevance are provided.

Materials and Methods

Two hundred herbalists agreed to participate but sixty-six specialized in treating mental and neurological disorders were interviewed on their traditional medical practice. Literature review was conducted to verify the experimentally validated pharmacological importance of the reported plants.

Results

Thirty-two plant species belonging to twenty-eight families were identified. Most plant species had either analgesic (50%), anxiolytic (18.8%), or anticonvulsant (15.6%) properties. Others had reported sedative, anti-Alzheimer's disease, motor coordination, antipsychotic, antidepressant, cognitive enhancement, and neuroprotective properties. While Ageratum conyzoides L. (Asteraceae) and Ocimum gratissimum L. (Lamiaceae) were the most commonly mentioned species with analgesic properties, Lantana camara L. (Verbenaceae) was the most-reported anxiolytic product, with Cymbopogon citratus DC. (Gramineae), Mangifera indica L., Tetrapleura tetraptera Schum Taub. (Fabaceae), and Persea Americana Mill (Lauraceae) being the most studied anticonvulsants.

Conclusions

This study provides the first report specifically on medicinal plants used in treating mental and neurological disorders in Ghana. Most of the identified plants have been scientifically confirmed to possess neuro- and psychopharmacological properties and may serve as templates for drug development.

Essential Oils and Their Constituents Targeting the GABAergic System and Sodium Channels as Treatment of Neurological Diseases

Essential oils and the constituents in them exhibit different pharmacological activities, such as antinociceptive, anxiolytic-like, and anticonvulsant effects. They are widely applied as a complementary therapy for people with anxiety, insomnia, convulsion, pain, and cognitive deficit symptoms through inhalation, oral administration, and aromatherapy. Recent studies show that essential oils are emerging as a promising source for modulation of the GABAergic system and sodium ion channels. This review summarizes the recent findings regarding the pharmacological properties of essential oils and compounds from the oils and the mechanisms underlying their effects. Specifically, the review focuses on the essential oils and their constituents targeting the GABAergic system and sodium channels, and their antinociceptive, anxiolytic, and anticonvulsant properties. Some constituents target transient receptor potential (TRP) channels to exert analgesic effects. Some components could interact with multiple therapeutic target proteins, for example, inhibit the function of sodium channels and, at the same time, activate GABAA receptors. The review concentrates on perspective compounds that could be better candidates for new drug development in the control of pain and anxiety syndromes.

Mosquito control with green nanopesticides: towards the One Health approach? A review of non-target effects

The rapid spread of highly aggressive arboviruses, parasites, and bacteria along with the development of resistance in the pathogens and parasites, as well as in their arthropod vectors, represents a huge challenge in modern parasitology and tropical medicine. Eco-friendly vector control programs are crucial to fight, besides malaria, the spread of dengue, West Nile, chikungunya, and Zika virus, as well as other arboviruses such as St. Louis encephalitis and Japanese encephalitis. However, research efforts on the control of mosquito vectors are experiencing a serious lack of eco-friendly and highly effective pesticides, as well as the limited success of most biocontrol tools currently applied. Most importantly, a cooperative interface between the two disciplines is still lacking. To face this challenge, we have reviewed a wide number of promising results in the field of green-fabricated pesticides tested against mosquito vectors, outlining several examples of synergy with classic biological control tools. The non-target effects of green-fabricated nanopesticides, including acute toxicity, genotoxicity, and impact on behavioral traits of mosquito predators, have been critically discussed. In the final section, we have identified several key challenges at the interface between "green" nanotechnology and classic biological control, which deserve further research attention.

Therapeutical strategies for anxiety and anxiety-like disorders using plant-derived natural compounds and plant extracts

Anxiety and anxiety-like disorders describe many mental disorders, yet fear is a common overwhelming symptom often leading to depression. Currently two basic strategies are discussed to treat anxiety: pharmacotherapy or psychotherapy. In the pharmacotherapeutical clinical approach, several conventional synthetic anxiolytic drugs are being used with several adverse effects. Therefore, studies to find suitable safe medicines from natural sources are being sought by researchers. The results of a plethora experimental studies demonstrated that dietary phytochemicals like alkaloids, terpenes, flavonoids, phenolic acids, lignans, cinnamates, and saponins or various plant extracts with the mixture of different phytochemicals possess anxiolytic effects in a wide range of animal models of anxiety. The involved mechanisms of anxiolytics action include interaction with γ-aminobutyric acid A receptors at benzodiazepine (BZD) and non-BZD sites with various affinity to different subunits, serotonergic 5-hydrodytryptamine receptors, noradrenergic and dopaminergic systems, glutamate receptors, and cannabinoid receptors. This review focuses on the use of both plant-derived natural compounds and plant extracts with anxiolytic effects, describing their biological effects and clinical application.

Culture-Bound Syndromes of a Brazilian Amazon Riverine population: Tentative correspondence between traditional and conventional medicine terms and possible ethnopharmacological implications

ETHNOPHARMACOLOGICAL RELEVANCE

It is not always possible to correlate the "emic" terms to the "etic" ones during ethnopharmacological surveys, especially regarding those related to Culture-Bound Syndromes (CBS). Nevertheless, it is the role of ethnopharmacology to address these correlations, since they are the basis for the understanding of potential bioactives.

AIM AND OBJECTIVES

This study reports the clinical manifestations and therapeutic resources used for the treatment of CBS among some riverine inhabitants of Brazilian Amazonia. An effort was made to establish a correspondence between the local "emic" terms of traditional medicine and the symptoms or diseases known by conventional medicine ("etic" terms). The ultimate goal was to gain insights to suggest further pharmacological studies with the local resources.

MATERIAL AND METHODS

Fieldwork was guided by methods of anthropology, botany and zoology-with the assistance of a doctor-among the traditional healing experts in Jaú National Park (during 199 days in 1995) and Unini River Extractive Reserve (210 days from 2008 to 2012).

RESULTS

Fifty-nine healers of different kinds were interviewed: a prayer-maker, medium, natural resource expert, massage therapist, midwife and snakebite healer. The clinical manifestations and healing resources of the following CBS were collected: "mau olhado" (evil eye), "quebrante" (chipping); "espante" (fright or susto); "doença do ar" (air diseases); "vento caído" (fallen wind); "derrame" (leakage); "mãe do corpo" (mother of the body) and "panema" (unlucky). The first three seem to be local variations of other CBSs already described in Latin America. "doença do ar", "vento caído", "derrame" and "mãe do corpo" seem to be folk terms for known conventional medical disorders, while "panema" is a yet undescribed Brazilian CBS that is possibly related to dysthymic disorder or depression and deserves further investigation. Treatments included prayer rituals, fumigation, baths and oral remedies using 25 plants and 10 animals.

CONCLUSION

It was possible to establish hypothetical correlations between CBS as described by the riverine population studied and some "etic" terms. The main importance of this is to help the proposition of target-oriented pharmacological studies of the natural resources used by these communities. Accordingly, the following plants are suggested to be submitted to further studies for antidepressant and anxiolytic activities: Siparuna guianensis, Mansoa alliacea, Leucas martinicensis, Petiveria alliacea, Annona montana and Alpinia nutans; for anti-seizure activity: Protium amazonicum, Protium aracouchini and Protium heptaphyllum; finally for antispasmodic activity: Leucas martinicensis.

Effects of aromatherapy on agitation and related caregiver burden in patients with moderate to severe dementia: A pilot study

We examined the effects of aromatherapy on agitation in patients with dementia and evaluated related caregiver burden. Patients and their caregivers from two hospitals in Turkey were selected and divided into an intervention group (n = 14) and a control group (n = 14). Patients were stratified according to their dementia phase and intake of antipsychotic medication. The intervention group received aromatherapy via massage and inhalation at home for 4 weeks. The control group received no intervention. Data were collected using the Neuropsychiatric Inventory (NPI), the Cohen-Mansfield Agitation Inventory (CMAI) and the Zarit Burden Interview (ZBI). At 2 and 4 weeks, the NPI scores were significantly lower in the intervention group (p < 0.05). At 4 weeks, the CMAI and ZBI scores were significantly lower in the intervention group (p < 0.05). In conclusion, after aromatherapy, agitation, neuropsychiatric symptoms, and caregiver distress significantly reduced, and aromatherapy prevented caregiver burden increase.

Mexican medicinal plants with anxiolytic or antidepressant activity: Focus on preclinical research

ETHNOPHARMACOLOGICAL RELEVANCE

Anxiety and depression are considered the most prevalent psychiatric disorders worldwide. In Mexico, the use of medicinal plants to alleviate the symptoms associated with these psychiatric disorders is increasing. However, there is little scientific evidence that validates the efficacy of these plants. This evidence needs to be critically revised, and further studied to provided scientific support for their use.

AIM OF THE STUDY

To identify the plants that are used in Mexico for the treatment of disorders related to anxiety and depression, and to review the current preclinical and when available, clinical information of these plants.

METHODS

We searched in scientific databases (Pubmed, Web of Science, Scopus and other web sources such as "Biblioteca digital de la medicina tradicional Mexicana" ) for Mexican plants used for the treatment of anxiety and depression that have been analyzed in preclinical studies. Additional information was obtained from published books. For this review, we also consider those plants used in Mexican traditional medicine for the treatment of "nervios," "susto" or "espanto;" common terms that describe symptoms related to anxiety and depression disorders.

RESULTS

The bibliographic search identified 49 plants used in Mexican traditional medicine for the treatment of disorders related to anxiety and depression. From all these plants, 59% were analyzed in preclinical research, and only 8% were tested in clinical studies; only a few of these studies tried to elucidate their mechanism of action. In general, it is proposed that the plant extracts interact with the GABAergic system. However, only part of these studies attempted to analyze other neurotransmitter systems. Finally, in some cases, drug-herbal interactions were reported.

CONCLUSIONS

There is a large number of Mexican medicinal plants used as a treatment for anxiety and depression disorders. Although some of these plants have been studied in preclinical research, in most cases these studies are preliminary, and the understanding of the mechanism of action is inconclusive. The need for systematic studies in preclinical and clinical research is evident, and efforts should be done to fulfill these research. Finally, it is important also to study possible drug-herbal interactions to establish specific recommendations for people that use these plants as anxiolytic or antidepressant treatments either alone or in combination with another type of medicine.

Concordance and incongruence in preclinical anxiety models: Systematic review and meta-analyses

Rodent defense behavior assays have been widely used as preclinical models of anxiety to study possibly therapeutic anxiety-reducing interventions. However, some proposed anxiety-modulating factors - genes, drugs and stressors - have had discordant effects across different studies. To reconcile the effect sizes of purported anxiety factors, we conducted systematic review and meta-analyses of the literature on ten anxiety-linked interventions, as examined in the elevated plus maze, open field and light-dark box assays. Diazepam, 5-HT1A receptor gene knockout and overexpression, SERT gene knockout and overexpression, pain, restraint, social isolation, corticotropin-releasing hormone and Crhr1 were selected for review. Eight interventions had statistically significant effects on rodent anxiety, while Htr1a overexpression and Crh knockout did not. Evidence for publication bias was found in the diazepam, Htt knockout, and social isolation literatures. The Htr1a and Crhr1 results indicate a disconnect between preclinical science and clinical research. Furthermore, the meta-analytic data confirmed that genetic SERT anxiety effects were paradoxical in the context of the clinical use of SERT inhibitors to reduce anxiety.

Comparative and synergistic activity of Rosmarinus officinalis L. essential oil constituents against the larvae and an ovarian cell line of the cabbage looper, Trichoplusia ni (Lepidoptera: Noctuidae)

BACKGROUND

Plant essential oils are usually complex mixtures, and many factors can affect their chemical composition. To identify relationships between the composition and bioactivity of the constituents, comparative and synergistic interactions of the major constituents of rosemary essential oil were evaluated against third-instar larvae and an ovarian cell line of the cabbage looper, Trichoplusia ni, via different methods of application.

RESULTS

The major constituents of the rosemary oil we used were 1,8-cineole, (±)-camphor, (+)-α-pinene and camphene. Via topical application to larvae, 1,8-cineole was identified as the major active compound, whereas via fumigation, 1,8-cineole and (±)-camphor, and in a cytotoxicity assay, (+)-α-pinene, were determined to be the major active principles. Several combinations of these constituents exhibited synergistic insecticidal activities when topically applied, particularly among combinations of three major constituents, (±)-camphor, (+)-α-pinene and camphene. A binary mixture of 1,8-cineole and (±)-camphor showed enhanced activity, with a synergy ratio of 1.72.

CONCLUSION

Based on our results, the insecticidal activity of rosemary oil appears to be a consequence of the synergistic interaction between 1,8-cineole and (±)-camphor, and (±)-camphor should be considered a promising synergizing agent.

Olfactory variation in mouse husbandry and its implications for refinement and standardization: UK survey of non-animal scents

With their highly sensitive olfactory system, the behaviour and physiology of mice are not only influenced by the scents of conspecifics and other species, but also by many other chemicals in the environment. The constraints of laboratory housing limit a mouse's capacity to avoid aversive odours that could be present in the environment. Potentially odorous items routinely used for husbandry procedures, such as sanitizing products and gloves, could be perceived by mice as aversive or attractive, and affect their behaviour, physiology and experimental results. A survey was sent to research institutions in the UK to enquire about husbandry practices that could impact on the olfactory environment of the mouse. Responses were obtained from 80 individuals working in 51 institutions. Husbandry practices varied considerably. Seventy percent of respondents reported always wearing gloves for handling mice, with nitrile being the most common glove material (94%) followed by latex (23%) and vinyl (14%). Over six different products were listed for cleaning surfaces, floors, anaesthesia and euthanasia chambers and behavioural apparatus. In all cases Trigene™ (now called Anistel™) was the most common cleaning product used (43, 41, 40 and 49%, respectively). Depending on the attribute considered, between 7 and 19% of respondents thought that cleaning products definitely, or were likely to, have strong effects on standardization, mouse health, physiology or behaviour. Understanding whether and how these odours affect mouse welfare will help to refine mouse husbandry and experimental procedures through practical recommendations, to improve the quality of life of laboratory animals and the experimental data obtained.

A Systematic Review of the Anxiolytic-Like Effects of Essential Oils in Animal Models

The clinical efficacy of standardized essential oils (such as Lavender officinalis), in treating anxiety disorders strongly suggests that these natural products are an important candidate source for new anxiolytic drugs. A systematic review of essential oils, their bioactive constituents, and anxiolytic-like activity is conducted. The essential oil with the best profile is Lavendula angustifolia, which has already been tested in controlled clinical trials with positive results. Citrus aurantium using different routes of administration also showed significant effects in several animal models, and was corroborated by different research groups. Other promising essential oils are Citrus sinensis and bergamot oil, which showed certain clinical anxiolytic actions; along with Achillea wilhemsii, Alpinia zerumbet, Citrus aurantium, and Spiranthera odoratissima, which, like Lavendula angustifolia, appear to exert anxiolytic-like effects without GABA/benzodiazepine activity, thus differing in their mechanisms of action from the benzodiazepines. The anxiolytic activity of 25 compounds commonly found in essential oils is also discussed.

Cymbopogon citratus industrial waste as a potential source of bioactive compounds

BACKGROUND

Cymbopogon citratus (Cc), commonly known as lemongrass, is a very important crop worldwide, being grown in tropical countries. It is widely used in the food, pharmaceutical, cosmetic and perfumery industries for its essential oil. Cc aqueous extracts are also used in traditional medicine. They contain high levels of polyphenols, which are known for their antioxidant and anti-inflammatory properties. Hydrodistillation of lemongrass essential oil produces an aqueous waste (CcHD) which is discarded. Therefore a comparative study between CcHD and Cc infusion (CcI) was performed to characterize its phytochemical profile and to research its antioxidant and anti-inflammatory potential.

RESULTS

HPLC-PDA/ESI-MS(n) analysis showed that CcI and CcHD have similar phenolic profiles, with CcHD presenting a higher amount of polyphenols. Additionally, both CcI and CcHD showed antioxidant activity against DPPH (EC50 of 41.72 ± 0.05 and 42.29 ± 0.05 µg mL(-1) respectively) and strong anti-inflammatory properties, by reducing NO production and iNOS expression in macrophages and through their NO-scavenging activity, in a dose-dependent manner. Furthermore, no cytotoxicity was observed.

CONCLUSION

The data of this study encourage considering the aqueous solution from Cc leaf hydrodistillation as a source of bioactive compounds, which may add great industrial value to this crop.